We can now turn to the problem of how this communication occurs. The independence of real objects from one another demands such an explanation: How can mutually withdrawn objects possibly interact, so as to produce real changes in one another? The latter are quite distinct from the mere phenomenal variations that sensual objects undergo in experience, because they can reconfigure the very intentional space within which experience occurs. Yet it is only within these intentional spaces that a real object can encounter the variable facades projected by other real objects, and only through these sensual vicars that any sort of contact can be established between them. The fact that all causal contact arises out of an intentional relation between an experiencing real object and an experienced sensual object that mediates between it and its real counterpart implies that the causal relation is not just vicarious, but also asymmetrical and buffered. It is asymmetrical because the relation has direction, proceeding from the object the vicar conceals to the object the vicar appears to. This means that causation can occur one-way between real objects, without reciprocation (e.g., when a bee is hit by an oncoming car, the bee may be destroyed while the car is entirely unscathed). And it is buffered because there are many contiguous sensual objects present in the same experience, and this does not result in interactions between the real objects they hide (e.g., the bee may be drawn into the path of the truck by an enticing flower, but the truck and the flower may be entirely unrelated). This means that a real object’s sincerity in encountering a sensual object is the condition of that object’s receptivity.
However, we are not causally affected by every object we experience. The phenomenal realms that real objects find themselves immersed in are filled to the brim with myriad sensual unities, many of which have no impact upon them at all. This means that intentional relations are not necessarily causal relations. So what more is there to causal contact than mere sincerity? Harman responds by invoking the link between causation and allure mentioned above. Genuine change is internal to a real object, insofar as it only occurs when a real object becomes connected to its qualities in regenerating its essence; but this nevertheless requires an external trigger, which can only take the form of some variation within the intentional space in which it is immersed. Harman proposes that the confrontations usually precipitated by such variation are insufficient to trigger causal contact, because the qualities encountered therein are still tied to the facade that hides the triggering object from the triggered object. It is only in allusion that these ties are broken, and the qualities allowed to orbit the real object underlying them (e.g., when the metaphorical comparison of the tree with a flame highlights the relevant qualities in a way that makes them alien to the tree with which we are familiar). Allure lets reality obliquely slide into appearance, striking the object that experiences it in a way that surpasses the sensual flux it is accustomed to, so that the accidental features of the affecting object catalyse the reshuffling of essential features within the affected object.
Nevertheless, the affected object does not strictly see the affecting object, even if it feels it in some specific aesthetic mode (e.g., as humorous) and to some specific degree of aesthetic intensity (e.g., as only mildly humorous). The brief suspension of causal independence that occurs in causal connection never really overcomes the corresponding epistemic excess. Allure may play an important role in enabling us to reconfigure the ways we think about entities, but it never amounts to knowledge of them. This is why Harman grants aesthetics a special philosophical privilege. According to him, examining the varieties of allure and their relationships gives us an insight into the metaphysical structure of reality, an insight that forever escapes the stale practice of epistemology. With the tenfold categorical schema derived from the fourfold, Harman has provided a general theory of objects—which he calls ontography—capable of application to the various specific domains of objects that compose the cosmos. Yet it is only through an extending of the sorts of aesthetic analysis indicated by his theory of allure that these domains can be fleshed out. Ultimately, Harman proposes an alliance of aesthetics and metaphysics that promises to lay bare the various regions of the cosmos to renewed philosophical inquiry. It now falls to us to assess this proposal, and its worth.